Electromechanical, active dual-redundancy, twin-motor actuator to operate a component of a vehicle

Abstract

Electromechanical actuator to operate a component of a vehicle provided with a housing formed by a lower element and a lid; a transmission arranged inside the housing and comprising an output shaft provided with a first symmetry axis and an intermediate shaft, which meshes with the output shaft and is provided with a second symmetry axis transverse to the first symmetry axis; and a pair of electric motors also arranged inside the housing; wherein each of the two electric motors rotates the output shaft through the intermediate shaft and wherein the two electric motors are provided with respective rotation axes parallel to each other and transverse to the first symmetry axis.

The invention claimed is: 
     
       1. An electromechanical actuator ( 1 ) to operate a component of an internal combustion engine and/or of a vehicle comprising:
 a housing ( 2 ), which is obtained through a lower element ( 3 ) and a lid ( 4 ); 
 a transmission, which is arranged inside the housing ( 2 ) and comprises an output shaft ( 9 ), which is provided with a first symmetry axis (X), and an intermediate shaft ( 18 ), which meshes with the output shaft ( 9 ) and is provided with a second symmetry axis (Y), which is transverse to the first symmetry axis (X); and 
 a pair of electric motors ( 31 ,  32 ), which are also arranged inside the housing ( 2 ); wherein each one of the two electric motors ( 31 ,  32 ) causes the rotation of the output shaft ( 9 ) through the intermediate shaft ( 18 ), and wherein the two electric motors ( 31 ,  32 ) are provided with respective rotation axes (Z 1 , Z 2 ), which are parallel to one another and transverse to the first symmetry axis (X); 
 wherein the two electric motors ( 31 ,  32 ) are arranged side by side and are provided, at one of their axial ends, with respective gears ( 29 ,  30 ) arranged on opposite sides of a common toothed wheel ( 20 ) of the intermediate shaft ( 18 ) with which they mesh so that the gears ( 29 ,  30 ) transmit the motion from the corresponding electric motor ( 31 ,  32 ) to the same end of the intermediate shaft ( 18 ); and 
 wherein at least one needle roller bearing is fitted on the output shaft ( 9 ) so as to lock the output shaft ( 9 ) in a radial direction and a plug ( 17 ) is placed to lock the output shaft ( 9 ) in an axial direction. 
 
     
     
       2. An actuator according to  claim 1 , wherein the rotation axes (Z 1 , Z 2 ) are parallel to the second symmetry axis (Y). 
     
     
       3. An actuator according to  claim 1 , wherein, at one of their axial ends, opposite the axial end provided with the respective gear ( 29 ,  30 ), both electric motors ( 31 ,  32 ) are connected to a respective first axial spring ( 33 ) designed to dampen the vibrations produced by the rotation of the respective electric motor ( 31 ,  32 ). 
     
     
       4. An actuator according to  claim 3 , wherein both electric motors ( 31 ,  32 ) are connected to a respective second radial spring ( 35 ), which is constrained by means of fixing means ( 36 ) and surrounds a stator casing of the electric motors ( 31 ,  32 ). 
     
     
       5. An actuator according to  claim 1 , wherein the intermediate shaft ( 18 ) is provided with a worm-screw helical wheel ( 22 ), which, in use, meshes with a toothed wheel ( 13 ) with helical teeth of the output shaft ( 9 ). 
     
     
       6. An actuator according to  claim 1 , wherein the output shaft ( 9 ) is provided, at its first end, with a magnet ( 14 ) obtained as an upper portion or appendage, having an annular shape, coaxial to the first symmetry axis (X) and made of a magnetic material, which, in use, faces the lid ( 4 ). 
     
     
       7. An actuator according to  claim 6 , wherein the magnet ( 14 ) and the toothed wheel ( 13 ) with helical teeth are arranged at the first coupling end ( 12 ), opposite a second output end ( 10 ) of the output shaft ( 9 ) connected to an interface lever ( 11 ) for the operation of the component. 
     
     
       8. An actuator according to  claim 1 , wherein two bearings ( 15 ,  16 ), preferably two needle roller bearings, are fitted on the output shaft ( 9 ) and a plug ( 17 ) or a sealing ring is interposed between the two bearings ( 15 ,  16 ) so as to lock the output shaft ( 9 ) in an axial direction. 
     
     
       9. An actuator according to  claim 1  and comprising at least one sensor ( 34 ), which is caused to be integral to an inner surface of the lid ( 4 ) in a position facing and close to the output shaft ( 9 ), so as to detect the rotary motion of the output shaft ( 9 ) around the first symmetry axis (X). 
     
     
       10. An actuator according to  claim 1 , wherein the housing ( 2 ) is obtained through a lower element ( 3 ) and a lid ( 4 ), which are suitably connected to each other by a plurality of closing clips ( 5 ) arranged on the periphery of the housing ( 2 ), and define internally a compartment (V); wherein both the electric motors ( 31 ,  32 ) are arranged inside the housing ( 2 ); and in that, inside the compartment (V), a seat ( 7 ) is formed coaxial to the first symmetry axis (X) and defined by a substantially cylindrical side wall ( 8 ), which cantileverly projects from the lower element ( 3 ) towards the outside of the housing ( 2 ) and is designed to house a portion of the output shaft ( 9 ).